1. Field of the Invention
The present invention relates to an electronic package for an integrated circuit.
2. Description of Related Art
Integrated circuits (ICs) are typically housed within a package that can be mounted to a printed circuit board. A conventional IC package includes an outer housing that encapsulates the integrated circuit and a lead frame that couples the IC to the printed circuit board. The lead frame has a plurality of leads that extend from the outside of the housing. The leads are commonly bent into a S shape configuration and soldered to surface pads on the printed circuit board.
Electronic packages are typically tested before being assembled to the printed circuit board. A conventional method of testing electronic packages is to place the package within a tester until the leads are in contact with a plurality of test pins. Signals are then transmitted between the IC and the tester to check the integrity of the package. To align the leads with the test pins, the corner leads of the package are placed within an alignment feature of the tester. The leads of the package are relatively small and weak and are thus susceptible to damage when placed within the tester. It is therefore desirable to test the package in a manner that will not damage the leads.
Another method of testing an electronic package is to place the test pins in contact with the leads before the leads are bent into the S-shaped configuration. In this method the lead frame has a rigid outer plastic frame that is molded along with the housing of the package. The outer frame provides structural stability for the leads during the handling and testing of the package. The ends of the leads are bent against the sides of the outer plastic frame. Test pins are then pushed into contact with the ends of the leads. After the package is tested, the outer plastic frame is removed and the leads are bent into the final shape. One disadvantage of this method of testing arises because the length of the leads that are tested are longer than the lead length that is actually soldered to the printed circuit board. The tester must then compensate for the additional impedance and noise associated with the extra lead length. Additionally, having to mold the outer plastic frame produces a larger number of mold defects and a lower production yield of the package. It would be desirable to have a package which can be accurately tested before the leads are bent, without either electrical compensation or increased risk of yield loss to reduce the probability of the leads becoming damaged.